Unusual point behaviour

[NormanQ4]

I have 12 sets of points set up as pairs using two R8247 decoders.

5 of the pairs act simutaneously while the 6th has a delay of about 2 seconds before the second point fires.

There is also a slight tick between the firings.

They function ok but the delay is quite puzzling.

Any clues would be helpful.

[St1ngr4y]

I have 12 sets of points set up as pairs using two R8247 decoders.

5 of the pairs act simutaneously while the 6th has a delay of about 2 seconds before the second point fires.

There is also a slight tick between the firings.

They function ok but the delay is quite puzzling.

Any clues would be helpful.

Hi Norman,

Do you have a set of red/green buttons on each point in a pair OR do the 5 pairs which work ok have one set of buttons between them, but the 6th has two pairs?

Ray

 

 

[NormanQ4]

All have one set of buttons to each point and all are wired up exactly the same and set up the same in RM.

[St1ngr4y]

Hi Norman,

When you click on a point button in RM, it actually fires the point twice, about a second apart, to make sure the point has switched. Usually you will hear a loud noise first, when the point changes, then a quiet click which is the second firing. If you have two points with the same address, each with a set of buttons, RM will fire the points three or four times, but usually only the first firing produces the loud noise, followed by two or three quiet clicks. Maybe the 6th point is a bit sticky and it is a secondary firing which is actually moving it?

Does the same apparent delay occur in both point movement directions?

Ray

[NormanQ4]

Thanks Ray, all the others fire on the first click and this point doesn't seem sticky, however I will check it out again to see if it's maybe just sticking enough to cause the delay.

[St1ngr4y]

Thanks Ray, all the others fire on the first click and this point doesn't seem sticky, however I will check it out again to see if it's maybe just sticking enough to cause the delay.

Does the same delay occur in both directions (left and right)?

 

 

[NormanQ4]

Yes both directions.

[Chrissaf]

From your description, I would deduce (maybe incorrectly) that you are operating the points from within RailMaster. I would also deduce given the number of points compared to the number of R8247 ports, that the six point pairs are wired in parallel and share the same R8247 port, thus only six of the available eight R8247 ports are used. I would deduce that in RailMaster track layout, where two points are configured as a pair they are given the same DCC address, so that clicking on either point control throws both of them as a pair. What I write next assumes the above deductions are correct.

.

Firstly regarding the ticks (clicks) between firing. When operating points using RailMaster, RM sends two sequential point firing commands. The reason being to be 'belt 'n' braces in case there is a sticky point motor or the first pulse is lost within the interaction between RM and the R8247. Secondly, where you have two points configured with the same DCC address in RM and you click on the point control icon of one of the pairs. RM sends out DCC commands sequentially, so the second point of the pair is fired by RM after a slight delay**. This results in multiple point firing pulses being sent by the R8247. It is probably these multiple pulses re-energizing an already thrown point motor that you can hear causing the audible click.

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Note** before writing this reply I tested my own point pair configuration in RM. When operating a point pair I counted three attempts by RM to fire the point. Two attempts for the point icon I had clicked and one for the other point of the pair. Why not four point firing attempts I do not know, maybe one of them gets lost within RM from the way the software is written. Theoretically, given that the two points have got the same DCC address, the second point of the pair in RM shouldn't generate a second firing attempt, but it does seem to for some reason.

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Now as to why the 6th pair experience a delay between the first and second point motors throwing. My initial thought is that there is a sticky point and it consistently needs a second or maybe even the third pulse## to complete its action. If you are using Elite (probably not, more likely e-link), but if you are using Elite, test what happens when you operate the 6th point pair from that. Elite only sends a single point operating pulse. You could then note what then happens to the second point motor of the pair. I would think that this would show up a potential sticky point more effectively. If it is not sticky, then as you say the 2 second delay is puzzling.

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Note## In my test documented above. I would estimate that I heard a delay of between 1.5 and 2 seconds between the first and third point operating attempt.

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Rhetorical question (a question that does not need an answer, just something for you to consider): Is the 6th point pair wired exactly as the other 5 pairs i.e wired in parallel both sharing the same R8247 port.

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EDIT: Spent so much time writing this reply, all the usual suspects got in with similar comments before me. Well at least we're all singing from the same hymn sheet.

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Note to self, must type faster.

[NormanQ4]

Problem solved.

The reverse polarity box was ticked in one of the points.

I guess I wasn't looking for the obvious.

[St1ngr4y]

Hi Chris,

"Note** before writing this reply I tested my own point pair configuration in RM. When operating a point pair I counted three attempts by RM to fire the point. Two attempts for the point icon I had clicked and one for the other point of the pair. Why not four point firing attempts I do not know, maybe one of them gets lost within RM from the way the software is written."

I've often wondered that. Maybe the first firing for the 2nd point is so close to the second firing of the 1st point that the CDU in the R8247 has had absolutely no time to recharge at all - not enough to generate a click of the point blades ?

Ray

[St1ngr4y]

Problem solved.

The reverse polarity box was ticked in one of the points.

I guess I wasn't looking for the obvious.

That makes sense - RM would be throwing the points one way, then the other 2 seconds later.

Ray